<template>
    <section class="real-app">
        <input type="text"
            class="add-input"
            autofocus="autofocus"
            placeholder="接下去做什么?"
            @keyup.enter="addTodo"
        >
        <item 
            :todo="todo"
            v-for="todo in filteredTodos"
            :key="todo.id"
            @del='deleteTodo'

        />
        <tabs
         :filter="filter" 
         :todos="todos"
         @toggle="toggleFilter"
         @clearAllCompleted="clearAllCompleted"
         />
    </section>
</template>

<script>
import Item from './item.vue'
import Tabs from './tabs.vue'
let id = 0


export default {
    data(){
        return {
            todos: [],
            filter: 'all'
        }
    },
    components:{
        Item,
        Tabs
    },
    computed:{
        filteredTodos(){
            if (this.filter === 'all'){
                return this.todos
            }
            const completed = this.filter === 'completed'
            return this.todos.filter(todo => completed === todo.completed)
        }
    },
    methods: {
        addTodo(e){
            this.todos.unshift({
                id: id++,
                content: e.target.value.trim(),
                completed: false
            })
            e.target.value = ''
        },
        deleteTodo(id){
            this.todos.splice(this.todos.findIndex(todo => todo.id == id), 1)
        },
        toggleFilter(state){
            this.filter = state
        },
        clearAllCompleted(){
            this.todos = this.todos.filter(todo => !todo.completed)
        }
    }
}
</script>

<style lang="stylus" scoped>
.real-app{
    width 600px
    margin 0 auto
    box-shadow 0 0 5px #666
    }
.add-input{
    position: relative;
    margin: 0;
    width: 100%;
    font-size: 24px;
    font-family: inherit;
    font-weight: inherit;
    line-height: 1.4em;
    border: 0;
    outline: none;
    color: inherit;
    padding: 6px;
    border: 1px solid #999;
    box-shadow: inset 0 -1px 5px 0 rgba(0, 0, 0, 0.2);
    box-sizing: border-box;
    font-smoothing: antialiased;
    padding: 16px 16px 16px 60px;
    border: none;
    box-shadow: inset 0 -2px 1px rgba(0,0,0,0.03);
    }
 .tab-container
    background-color #fff
    padding 0 15px
</style>